Retrospective Cohort Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplant. Sep 18, 2024; 14(3): 95233
Published online Sep 18, 2024. doi: 10.5500/wjt.v14.i3.95233
Matched pair analysis of the effect of longer hypothermic machine perfusion time on kidney transplant outcomes
Carlos Verdiales, Luke Baxter, Hyun Ja Lim, Gavin Beck, Michael A Moser
Carlos Verdiales, Gavin Beck, Michael A Moser, Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W8, Canada
Luke Baxter, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W8, Canada
Luke Baxter, Canada and Northern Ontario School of Medicine, Thunder Bay, Ontario P7B 5E1, Canada
Hyun Ja Lim, Department of Community Health and Epidemiology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W8, Canada
Author contributions: Verdiales C, Baxter L, Lim HJ, Beck G, and Moser MA designed the research study; Verdiales C, Baxter L, and Moser MA collected the data; Verdiales C, Lim HJ, Beck G, and Moser MA analyzed and interpreted the data; Verdiales C, Lim HJ, Beck G, and Moser MA wrote the manuscript. All authors have read and approved the final manuscript.
Institutional review board statement: This study was reviewed and approved by our local Research Ethics Board (Bio-REB#1894).
Informed consent statement: The need to obtain consent from each patient was waived.
Conflict-of-interest statement: There is no conflict of interest to declare.
Data sharing statement: The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. All data provided will be de-identified to ensure patient confidentiality and comply with ethical standards. Access to Data: Requests for access to the data should be addressed to Dr. M. Moser, mike.moser@usask.ca, University of Saskatchewan.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Michael A Moser, FRCS (Gen Surg), MD, MSc, Professor, Department of Surgery, University of Saskatchewan, 103 Hospital Drive, Saskatoon, Saskatchewan S7N 0W8, Canada. mike.moser@usask.ca
Received: April 5, 2024
Revised: May 31, 2024
Accepted: June 26, 2024
Published online: September 18, 2024
Processing time: 117 Days and 2 Hours
Abstract
BACKGROUND

Hypothermic machine perfusion (HMP) has demonstrated benefits in terms of early kidney transplant function compared to static cold storage. While longer preservation times have shown detrimental effects, a previous paired study indicated that longer pump times (the second kidney in a pair) might lead to improved outcomes.

AIM

To revisit the prior paired study's somewhat unexpected results by reviewing our program's experience.

METHODS

A total of 61 pairs of transplant recipients who received kidneys from the same donor (2012-2021) were analyzed. Patients were divided into two groups depending on whether they were transplanted first (K1) or second (K2). Therefore, the patients in each pair had identical donor characteristics, except for time on the pump. Statistical analyses included Kaplan-Meyer analysis and paired tests, including McNemar's test, student's paired t-test, or Wilcoxon's test, as appropriate.

RESULTS

The two groups of recipients had similar demographics (age, body mass index, diabetes, time on dialysis, sensitization and retransplants). Cold ischemic times for K1 and K2 were 8.9 (95%CI: 7.9, 9.8) and 14.7 hours (13.7, 15.8) (P < 0.0001), respectively. Overall, K2 had a higher rate of freedom from biopsy-proven acute rejection at 1 year (P = 0.015). Delayed graft function was less common in K2, 12/61 (20%) than in K1, 20/61 (33%) (P = 0.046). Finally, K2 showed a higher graft survival than K1 (P = 0.023).

CONCLUSION

Our results agree with a previous study that suggested possible advantages to longer pump times. Both studies should encourage further research into HMP's potential anti-inflammatory effect.

Keywords: Hypothermic machine perfusion, Paired kidney study, Early acute rejection

Core Tip: Our study assesses the impact of longer hypothermic machine perfusion (HMP) times on kidney transplant outcomes using a matched pair analysis of 61 kidney pairs. Our results agree with previous findings, showing that the second kidney, subjected to longer HMP times, has improved freedom from biopsy-proven acute rejection within the first year. These outcomes suggest that extended HMP durations, when applied judiciously, may confer anti-inflammatory benefits. This supports the potential for further basic science research and future optimization of perfusion protocols.